291064721 has 4 divisors (see below), whose sum is σ = 297833712. Its totient is φ = 284295732.

The previous prime is 291064691. The next prime is 291064723. The reversal of 291064721 is 127460192.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-291064721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (291064723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3384431 + ... + 3384516.

It is an arithmetic number, because the mean of its divisors is an integer number (74458428).

Almost surely, 2^291064721 is an apocalyptic number.

It is an amenable number.

291064721 is a deficient number, since it is larger than the sum of its proper divisors (6768991).

291064721 is an equidigital number, since it uses as much as digits as its factorization.

291064721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6768990.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 291064721 is about 17060.6190098718. The cubic root of 291064721 is about 662.7196630555.

The spelling of 291064721 in words is "two hundred ninety-one million, sixty-four thousand, seven hundred twenty-one".